About the Vaccine

Shingles Vaccine Composition and Dosage

Zoster vaccine, when reconstituted as directed on the package label using the supplied diluent, contains a minimum of 19,400 PFU of Oka/Merck strain of varicella zoster virus. The minimum potency of zoster vaccine is at least 14 times the potency of varicella vaccine (Varivax®), which contains a minimum of 1,350 PFU, and is similar in potency to the varicella zoster virus content of measles-mumps-rubella-varicella vaccine (ProQuad®).

Zoster vaccine is administered subcutaneously as a single dose in the deltoid region. The vaccine should not be injected intramuscularly. However, it is not necessary to repeat vaccination if it is administered intramuscularly.

The vaccine should be administered immediately after reconstitution to minimize loss of potency. Any unused vaccine should be discarded if not used within 30 minutes.

Vaccine Effectiveness and Duration of Protection

In a large clinical trial involving more than 38,000 people 60 years old and older, the zoster vaccine reduced the overall incidence of zoster by 51% and the incidence of post-herpetic neuralgia by 67%. The efficacy of the vaccine in preventing zoster was higher in people 60 to 69 years old (vaccine efficacy: 64%) than in people older than 70 years (vaccine efficacy: 38%). Zoster vaccine efficacy wanes within the first 5 years after vaccination, and protection beyond 5 years is uncertain.

Studies are ongoing to assess the duration of protection from one dose of zoster vaccine and the need, if any, for booster doses.

There are no comprehensive data on the effectiveness of zoster vaccine in treating shingles once it occurs, and the vaccine is not licensed for this indication.